Answer:
72.57 grams
Explanation:
The mass percentage of gold in the ore is 0.19 %
The mass of ore used = 23 kg
The mass of gold in the ore = 
moles of gold in the given mass of ore =
As per given equation four moles of Au is giving four moles of complex compound on reacting with NaCN
Then in second reaction two moles of the complex is reacting with one mole of Zinc
Thus two moles of gold are reacting with one mole of Zinc
The moles of Zinc needed = 0.5 X 2.22 mol = 1.11 moles
The mass of Zinc needed = moles X atomic mass =1.11 X 65.38 = 72.57 grams
Answer:
The answer is "5.18
".
Explanation:
It's a question of chemistry. Therefore, the following solution is provided:
We will first determine the solution's pOH. The following can possible:
The concentration of Hydroxide ion ![[OH^{-}] = 1.5\times 10^{-9}\ M](https://tex.z-dn.net/?f=%5BOH%5E%7B-%7D%5D%20%3D%201.5%5Ctimes%2010%5E%7B-9%7D%5C%20M)
![pOH =?\\\\pOH = -\log [OH^{-}]\\\\pOH = -\log 1.5\times 10^{-9}\\\\pOH = 8.82\\\\](https://tex.z-dn.net/?f=pOH%20%3D%3F%5C%5C%5C%5CpOH%20%3D%20-%5Clog%20%5BOH%5E%7B-%7D%5D%5C%5C%5C%5CpOH%20%3D%20-%5Clog%201.5%5Ctimes%2010%5E%7B-9%7D%5C%5C%5C%5CpOH%20%3D%208.82%5C%5C%5C%5C)
Furthermore, the pH of the solution shall be established. It was provided as follows:
When collecting all the like terms:
Therefore, the solution of pH is 5.18.
U need to do it in cronological order
Answer:
The answer is 15 g
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
density of Chloroform = 1.5 g/ml
volume = 10 mL
We have
mass = 1.5 × 10
We have the final answer as
<h3>15 g</h3>
Hope this helps you
Answer:
0.5 mol
Explanation:
Given data:
Number of atoms of He = 3.01 ×10²³
Number of moles = ?
Solution:
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.02 × 10²³ is called Avogadro number.
1 mole = 6.02 × 10²³ atoms
3.01 ×10²³ atoms × 1 mol / 6.02 × 10²³ atoms
0.5 mol
